As Paul, Silas, and Timothy traveled, Luke said, “And as they went through the cities, they delivered to them the decrees to keep, which were determined by the apostles and elders at Jerusalem. So the churches were strengthened in the faith, and increased in number daily” (Acts 16:4-5).
The evangelistic team passed out the letter from the Jerusalem meeting concerning the matter of whether Gentiles had to be circumcised, and the team strengthened the churches in the faith, then an increase in numbers came.
Somehow we have to speak the word of God. Without that, Christians cannot be strengthened in the faith, and people are not going to be added to the church because they have not heard the word of God.
Therefore, do everything you can to see that people hear what God says. You will be planting or watering, and God shall give the increase.